Toxic Effects of Deltamethrin on the Histological Structure of the Urogenital System in Adult Male Rabbits and the Protective Role of Folic Acid Antioxidants

Abstract

Deltamethrin insecticide has been widely applied for agricultural and veterinary purposes. However, exposure to it is attributed to several deleterious impacts on animals and human health. The study aimed to evaluate the negative impacts of deltamethrin on the normal architecture of kidney and testes of adult male rabbits on long-term exposure and manifested the possible protective effect of folic acids against this insecticide toxicity. Twenty adult male rabbits were divided into four groups: group 1 (control group), group 2 administered 1.28mg/Kg BW of deltamethrin, group 3 received 5mg/kg BW of folic acid, and group 4 was given a combination of deltamethrin and folic acid. The treatment was applied once daily for 12 weeks. The specimens were processed and stained with H&E and PAS stain for light microscopic examination. Deltamethrin-treated rabbits showed tubular injury in the form of loss of brush border, dropping off nuclei, and karyolysis of tubular cells. In addition, flattening of the tubular epithelium and dilatation of the renal tubules were also observed. A glomerulus appeared with mesangial cell expansion and capillary tuft congestion. The peritubular lymphocytic infiltration and areas of hemorrhage were noticed in the interstitium. Kidney sections stained with PAS demonstrated a marked decrease in carbohydrate content of tubular epithelium and disruption of membrane structures, which are induced by deltamethrin toxicity. The same findings were also seen in the combination group, indicating no role of folic acids as antioxidants. Regarding testicular tissue, deltamethrin induced hydropic degeneration of seminiferous tubules, leading to destruction of stratified germinal layers and a series of spermatogonia with focal loss of spermatid production. The interstitial cells of Leydig between tubules revealed a marked proliferation. In spite of treated animals, the combination group showed a focal improvement of spermatogenesis with a return to the normal length of spermatogonia layers. Deltamethrin induced obvious structural changes to the kidneys and testes of rabbits; therefore, it should be carefully limited at farms and animal houses to avoid serious impacts on human health. Application of antioxidants such as folic acid could be useful to ameliorate testes damage while showing a beneficial effect on renal structures